The invention relates to semiconductor processing methods, and more particularly to a low temperature process.
The invention provides reliable, uniform, repeatable and void-free semiconductor bonding using a low temperature process. The invention achieves molecular bonding of two closely spaced surfaces through a chemical vapor reaction that results in the deposition and growth of a metallic element to provide the bonding. The molecular bonding is achieved without the need of any fluxes or undesirable high temperatures otherwise required by present methodologies. In addition, the invention eliminates contamination of devices and circuits, is cost effective, and provides high yield.
It is known in the prior art to use chemical vapor deposition to define metal lines on a surface: "Laser-Direct-Writing Processes: Metal Deposition, Etching, and Applications to Microcircuits", Jerry G. Black et al, J. Vac. Sci. Technol. B 5(1), Jan/Feb 1987, pages 419-422; "On The Applications of Laser-Direct-Writing Techniques, To GaAs Monolithic Microwave Integrated Circuits", C. L. Chen et al, GaAs IC Symposium, IEEE 1987, pages 167-170; "Selective Electroless Metal Deposition for Integrated Circuit Fabrication", Chiu H. Ting et al, J. Electrochem. Soc., Vol. 136, No. 2, February 1989, pages 456-462. The present invention enables use of this technology to provide a metallic molecular bond interface bonding a semiconductor chip to a substrate.